U.S. patent number 7,304,729 [Application Number 11/348,325] was granted by the patent office on 2007-12-04 for survey system.
This patent grant is currently assigned to Sokkia Co., Ltd.. Invention is credited to Minoru Chiba, Nobuyuki Nishita, Satoshi Yasutomi.
United States Patent |
7,304,729 |
Yasutomi , et al. |
December 4, 2007 |
Survey system
Abstract
A survey system is made up of a target and a surveying
instrument provided with an automatic collimator that automatically
collimates the target. The target includes a guide light
transmitter that emits guide light, an azimuth angle sensor that
detects a direction angle (.theta.A, .theta.B) at which the target
is directed, and a central processing unit that sends a rotation
command, which includes the rotational direction of the instrument
body, to the surveying instrument. The central processing unit
determines the rotational direction of the instrument body based on
an angular difference (.theta.B-.theta.A) between a direction angle
(.theta.A) obtained when the target is caused to approximately face
the surveying instrument at the last measurement and a direction
angle (.theta.B) obtained when the target is caused to
approximately face the surveying instrument at the present
measurement.
Inventors: |
Yasutomi; Satoshi
(Ashigarakami-gun, JP), Chiba; Minoru
(Ashigarakami-gun, JP), Nishita; Nobuyuki
(Ashigarakami-gun, JP) |
Assignee: |
Sokkia Co., Ltd. (Atsugi-shi,
Kanagawa, JP)
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Family
ID: |
36709911 |
Appl.
No.: |
11/348,325 |
Filed: |
February 7, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060176473 A1 |
Aug 10, 2006 |
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Foreign Application Priority Data
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Feb 9, 2005 [JP] |
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2005-033639 |
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Current U.S.
Class: |
356/141.3 |
Current CPC
Class: |
G01C
1/00 (20130101); G01C 1/02 (20130101); G01C
15/00 (20130101); G01C 15/002 (20130101) |
Current International
Class: |
G01B
11/26 (20060101) |
Field of
Search: |
;356/141.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3075384 |
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Jun 2000 |
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JP |
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2000-346645 |
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Dec 2000 |
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JP |
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2003-273471 |
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Sep 2003 |
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JP |
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2004-144899 |
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May 2004 |
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JP |
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Primary Examiner: Tarcza; Thomas H.
Assistant Examiner: Ratcliffe; Luke
Attorney, Agent or Firm: Westerman, Hattori, Daniels &
Adrian, LLP.
Claims
The invention claimed is:
1. A survey system comprising a target and a surveying instrument
provided with an automatic collimator that automatically collimates
the target, the target comprising a guide light transmitter that
emits guide light; an azimuth angle sensor that detects a direction
angle at which the target is directed; and a rotation command means
for sending a rotation command to the surveying instrument, the
surveying instrument comprising a rotation means for directing a
body of the surveying instrument toward the target by receiving the
guide light when the rotation command is received, wherein the
rotation command means or the rotation means determines a
rotational direction of the body of the surveying instrument based
on an angular difference between a direction angle obtained when
the target is caused to substantially exactly face the surveying
instrument at the last measurement and a direction angle obtained
when the target is caused to substantially exactly face the
surveying instrument at the present measurement.
2. The survey system as described in claim 1, wherein the rotation
command means or the rotation means determines the rotation angle
of the body of the surveying instrument to be the angular
difference.
3. The survey system as described in claim 1, wherein the rotation
command means or the rotation means rotates the body of the
surveying instrument in a rotational direction determined based on
the angular difference if the angular difference is greater than a
maximum estimated error angle of the azimuth angle sensor, and the
rotation command means or the rotation means determines an
excessive angle that is greater by the maximum estimated error
angle than the angular difference, then rotates the body of the
surveying instrument by the excessive angle, and reverses the body
of the surveying instrument if the angular difference of the
direction angle is smaller than the maximum estimated error
angle.
4. The survey system as described in claim 1, wherein if an angular
difference of the direction angle is greater than the sum of the
maximum estimated error angle of the azimuth angle sensor and a
safe error angle obtained by affording a margin for the error
angle, the rotation command means or the rotation means rotates the
body of the surveying instrument in a rotational direction
determined based on the angular difference, and if the angular
difference of the direction angle is greater than the maximum
estimated error angle and is smaller than the sum of the maximum
estimated error angle and the safe error angle, the rotation
command means or the rotation means determines an excessive angle
greater by the sum of the maximum estimated error angle and the
safe error angle than the angular difference, then rotates the body
of the surveying instrument by the excessive angle, and reverses
the body of the surveying instrument, and if the angular difference
of the direction angle is smaller than the maximum estimated error
angle, the rotation command means or the rotation means determines
an excessive angle greater by the maximum estimated error angle
than the angular difference and a return angle equal to the sum of
twice the maximum estimated error angle and the safe error angle,
then rotates the body of the surveying instrument by the excessive
angle, then reverses the body of the surveying instrument by the
return angle, and again rotates the body of the surveying
instrument in the direction determined first.
5. The survey system as described in any one of claims 1, 2, 3, and
4, wherein the azimuth angle sensor is a magnetic sensor.
Description
TECHNICAL FIELD
The present invention relates to a survey system that can remotely
control a surveying instrument from a target side by a single
operator.
BACKGROUND ART
In order to measure the position of a survey point or the like by
using a conventional surveying instrument such as a total station
(electric distance/angle meter), it was necessary to collimate a
target placed at the survey point. In recent years, a surveying
instrument having an automatic collimator has appeared on the
market in order to reduce labor required to collimate a target and
in order to reduce collimation errors committed by an operator. An
automatic collimator is a device for determining the direction of a
target by emitting a beam of collimation light along the
collimation axis (optical axis) of a telescope of the surveying
instrument and by receiving the collimation light reflected from
the target so as to automatically and accurately direct the
telescope toward the target. The surveying instrument having the
thus structured automatic collimator has come to include a remote
control device so that survey operations can be performed even by a
single operator from a location away from the body of the surveying
instrument.
However, a conventional problem resides in the fact that, when the
surveying instrument having the automatic collimator or the
surveying instrument having the remote control device performs a
survey in accordance with a command emitted from the remote control
device, the telescope must scan a wide range in order to set the
target within a narrow visual field of the telescope, and hence
much time is consumed for automatic collimation, and the survey
cannot be smoothly performed.
To solve this problem, the present applicant has filed an
application concerning a survey system according to which a target
is swiftly found by emitting guide light from the target side, and
time required for automatic collimation is shortened (see Patent
Document 1 mentioned below). FIG. 8 to FIG. 10 show this survey
system.
As shown in FIG. 8, the survey system is made up of a surveying
instrument 50 having an automatic collimator and a target 60 having
a reflecting prism (retro reflector) 62 that reflects rays of light
in the direction of the incidence of the rays. The surveying
instrument 50 has a horizontally rotatable instrument body 52
provided on a leveling plate (not shown) fixed onto a tripod 48 and
a vertically rotatable telescope 54 provided in the instrument body
52. On a leveling plate 61 fixed onto a tripod 48, the target 60
has a reflecting prism 62 that reflects rays of collimation light
58 emitted from the surveying instrument 50 toward the surveying
instrument 50 and a guide light transmitter 66 that emits rays of
guide light 64 giving information about the direction of the target
60 toward the surveying instrument 50. The guide light 64 is
modulated so that the surveying instrument 50 can recognize the
guide light 64. Likewise, the collimation light 58 is modulated so
that the surveying instrument 50 can recognize the collimation
light 58.
The guide light transmitter 66 forms a wide fan beam that is
vertically narrow and is horizontally wide. To form the fan beam,
light emitted from a light source is diverged by a light
transmitting lens that is a cylindrical lens. After that, the guide
light transmitter 66 swings in the vertical direction and causes
the guide light 64 to scan in the vertical direction.
The instrument body 52 of the surveying instrument 50 has a
direction detector 56 that detects the direction of the guide light
64 emitted from the guide light transmitter 66. Since the guide
light 64 scans in the vertical direction with a fan beam, the
direction detector 56 can detect the direction of the guide light
transmitter 66 even when a large difference in height lies between
the surveying instrument 50 and the target 60 and even when these
two elements do not exactly face each other.
The surveying instrument 50 and the target 60 have wireless devices
70 and 72, respectively, for transmitting command signals and
survey results by radio 65 therebetween. The wireless devices 70
and 72 have non-directional antennas, respectively, so that
communications can be exchanged even when the surveying instrument
50 and the target 60 do not substantially face each other, and the
wireless devices 70 and 72 communicate with each other by radio
waves 65.
Referring now to the block diagram of FIG. 9, a description will be
given of the respective internal structures of the surveying
instrument 50 and the target 60 that constitute the survey
system.
The surveying instrument 50 includes a driving portion 101 that
directs the telescope 54 toward the reflecting prism 62, a
measuring portion 109 that measures a horizontal angle and a
vertical angle of the telescope 54, a collimation light emitting
portion 118 that emits collimation light 58 toward the reflecting
prism 62, a collimation light receiver 120 that receives
collimation light 58 reflected by the reflecting prism 62, a
storage portion 122 that stores data such as measured angle values,
a central processing unit (CPU) 100 connected to the driving
portion 101, the collimation light emitting portion 118, the
measuring portion 109, the collimation light receiver 120, and the
storage portion 122, and a transmitted-light receiving portion (not
shown) for calculating the distance between the reflecting prism 62
and the surveying instrument 50. Various commands and data can also
be input from an operating/inputting portion 124 to the central
processing unit 100.
The driving portion 101 is made up of a horizontal motor 102 that
horizontally rotates the instrument body 52, a vertical motor 106
that vertically rotates the telescope 54, and a horizontal driving
portion 104 and a vertical driving portion 108 that supply driving
current to the motors 102 and 106, respectively. The measuring
portion 109 is made up of a horizontal encoder 111 that
horizontally rotates together with the instrument body 52, a
vertical encoder 110 that vertically rotates together with the
telescope 54, a horizontal angle measuring portion 112 and a
vertical angle measuring portion 116 that read the rotation angles
of the encoders 111 and 110, respectively, and a distance measuring
portion (not shown). The distance measuring portion may be either a
pulse-type distance measuring system or a phase-difference-type
distance measuring system.
The surveying instrument 50 additionally includes an automatic
collimator that automatically directs the optical axis (collimation
axis) of the telescope 54 toward the reflecting prism 62. The
automatic collimator is made up of the central processing unit 100,
the collimation light emitting portion 118, the collimation light
receiver 120, and the driving portion 101. The automatic collimator
emits collimation light 58 from the collimation light emitting
portion 118, then receives the collimation light 58 reflected and
returned from the reflecting prism 62 by means of the collimation
light receiver 120, then determines the direction of the reflecting
prism 62 by means of the central processing unit 100, and controls
the driving portion 101 so that the optical axis of the telescope
54 can be directed toward the reflecting prism 62. The optical axis
of the automatic collimator and the optical axis of the optical
system of the distance measuring portion are coaxial.
The surveying instrument 50 additionally has a collimation
preparing means for pre-directing the telescope 54 toward the
target 60 before starting the automatic collimator. The collimation
preparing means is made up of the direction detector 56, the
wireless device 70, the driving portion 101, and the central
processing unit 100 connected thereto. Based on an output signal
emitted from the direction detector 56, the collimation preparing
means directs the telescope 54 toward the guide light transmitter
66, and starts automatic collimation when it is determined that the
telescope 54 has been directed approximately toward the target
60.
On the other hand, the target 60 has a central processing unit 80
connected to the guide light transmitter 66 and to the wireless
device 72, in addition to the reflecting prism 62, the guide light
transmitter 66, and the wireless device 72. An operating/inputting
portion 82 that inputs various commands and data and a display 84
that displays a state of the target 60 or a state of the surveying
instrument 50 are connected to the central processing unit 80.
Referring now to FIG. 10, a description will be given of a
measuring process in the survey system.
When the survey system is started, the process proceeds to step S1,
at which the target 60 emits guide light 64 from the guide light
transmitter 66. The process then proceeds to step S2, at which a
horizontal rotation command signal to horizontally rotate the
instrument body 52 is transmitted to the surveying instrument 50.
The surveying instrument 50 then receives the horizontal rotation
command signal at step S101. The process then proceeds to step
S102, at which a horizontal rotation starting notice is transmitted
to the target 60. The target 60 confirms the horizontal rotation of
the instrument body 52 at step S3, and thereby knows that the
surveying instrument 50 has started the horizontal search of the
guide light 64.
On the other hand, on the side of the surveying instrument 50, the
process proceeds to step S103, at which the instrument body 52 is
horizontally rotated. The process then proceeds to step S104, at
which the horizontal direction of the target 60 is detected by
receiving the guide light 64. If the guide light 64 cannot be
received in predetermined time here, the process proceeds to step
S105, at which an error notice is transmitted to the target 60.
After the target 60 receives the error notice at step S4, the
process proceeds to step S5, at which the target 60 causes the
display 84 to display a horizontal detection error, and is
stopped.
If the guide light 64 is received at step S104, the process
proceeds to step S106, at which the horizontal position of the
telescope 54 is adjusted toward the guide light transmitter 66, and
the horizontal rotation of the instrument body 52 is stopped. The
process then proceeds to step S107, at which a guide light OFF
command is transmitted to the target 60. When the guide light OFF
command is received at step S6, the target 60 recognizes that the
horizontal search of the guide light transmitter 66 has been
completed in the surveying instrument 50, and therefore the process
proceeds to step S7, at which the guide light 64 is turned off. The
process then proceeds to step S8, at which the guide light OFF
notice is transmitted to the surveying instrument 50.
If the surveying instrument 50 confirms the guide light OFF notice
at step S108, the process proceeds to step S109, at which
collimation light 58 is emitted. The process then proceeds to step
S110, at which the notice of starting the vertical rotation of the
telescope 54 is transmitted to the target 60. The vertical rotation
notice is confirmed at step S9, and thereby the target 60
recognizes that the surveying instrument 50 has started the
vertical search of the target 60. On the other hand, on the side of
the surveying instrument, the process proceeds to step S111, at
which the telescope 54 is vertically rotated, and the vertical
search of the target 60 is continued.
The process then proceeds to step S112, at which the surveying
instrument 50 emits collimation light 58, and the collimation light
58 reflected and returned from the target 60 is received, whereby
the vertical direction of the target 60 is detected. If the
collimation light 58 cannot be received here, the process returns
to step S101, at which a flow procedure is repeated, or the process
proceeds to step S113, at which an error notice is transmitted to
the target 60. If the target 60 confirms the error notice at step
S10, the process proceeds to step S11, at which the target 60
causes the display 84 to display a vertical direction detecting
error, and is stopped.
If the collimation light 58 is received at step S112, the process
proceeds to step S114, at which the telescope 54 is adjusted at the
vertical position of the target 60, and the telescope 54 is
stopped. The process then proceeds to step S115, at which a
collimating operation is started, and a notice to the effect that a
collimating operation is being carried out is transmitted to the
target 60. The target 60 confirms that a collimating operation is
being carried out at step S12, whereby the surveying instrument 50
recognizes that the automatic collimator has been started. On the
other hand, on the side of the surveying instrument 50, the process
proceeds to step S116, at which the automatic collimating operation
is continued.
If the collimating operation cannot be satisfactorily collimated
out at step S116, the process proceeds to step S117, at which an
error notice is transmitted to the target 60. If the target 60
confirms the error notice at step S13, the process proceeds to step
S14, at which the target 60 causes the display 84 to display a
collimation error, and is stopped. If the collimating operation is
satisfactorily collimated out at step S116, the process proceeds to
step S118, at which a collimation completion notice is transmitted
to the target 60. As a result, the target 60 recognizes that
automatic collimation has been completed in the surveying
instrument 50 at step S15.
The process then proceeds to step S119, at which the surveying
instrument 50 performs distance and angle measuring operations. The
process then proceeds to step S120, at which measured distance and
angle values are transmitted to the target 60. The target 60
confirms the measured distance and angle values at step S16, and
then causes the display 84 to display the survey results of the
measured distance and angle values and other results, and the
survey is ended.
In a case in which the errors are displayed on the display 84, and
operations are stopped by these errors, it is recommended to remove
the causes of the errors and then re-start the operation of the
survey system.
According to this survey system, since the fan-shaped beam of guide
light 64 is emitted from the side of the target 60 while scanning,
the guide light 64 having adequate intensity can be emitted to a
large range with less electric power, and the surveying instrument
50 can swiftly find the target 60, so that time required to
complete automatic collimation can be shortened.
[Patent Document 1] Japanese Patent Application No. 2004-023614
DISCLOSURE OF INVENTION
[Problems to be Solved by the Invention]
However, even in the surveying instrument 50 disclosed in the
application mentioned above, a conventional problem resides in the
fact that, if a proper command is not given as to whether the
instrument body 52 is first rotated clockwise or counterclockwise,
a case will arise in which the target 60 is finally caught by
rotating the instrument body 52 by approximately 360 degrees if
circumstances require, and time required for automatic collimation
cannot be sufficiently shortened although the target 60 can be
swiftly caught by slightly rotating the instrument body 52 in
ordinary cases. This problem can be easily solved by attaching a
button used to indicate its rotational direction to the target 60
and by allowing an operator to indicate the rotational direction of
the instrument body 52. However, this solution causes the problem
of increasing a burden imposed on the operator.
The present invention has been made in consideration of the
foregoing problem, and it is an object of the present invention to
provide a surveying instrument capable of shortening time required
for automatic collimation as much as possible without increasing a
burden imposed on an operator, although the surveying instrument
has already been capable of swiftly finding the target and capable
of shortening time required for automatic collimation as much as
possible by emitting guide light from the target side.
[Means for Solving the Problem]
To achieve the object, the invention according to Claim 1 is
characterized in that a survey system comprises a target and a
surveying instrument including an automatic collimator that
automatically collimates the target, and the target comprises a
guide light transmitter that emits guide light, an azimuth angle
sensor that detects a direction angle at which the target is
directed, and a rotation command means for sending a rotation
command to the surveying instrument, and the surveying instrument
comprises a rotation means for directing a body of the surveying
instrument toward the target by receiving the guide light when the
rotation command is received, and the rotation command means or the
rotation means determines a rotational direction of the body of the
surveying instrument based on an angular difference between a
direction angle obtained when the target is caused to substantially
exactly face the surveying instrument at the last measurement and a
direction angle obtained when the target is caused to substantially
exactly face the surveying instrument at the present
measurement.
The invention according to Claim 2 is characterized in that, in the
invention according to Claim 1, the rotation command means or the
rotation means determines the rotation angle of the body of the
surveying instrument to be the angular difference.
The invention according to Claim 3 is characterized in that, in the
invention according to Claim 1, the rotation command means or the
rotation means rotates the body of the surveying instrument in a
rotational direction determined based on the angular difference if
the angular difference is greater than a maximum estimated error
angle of the azimuth angle sensor, and the rotation command means
or the rotation means determines an excessive angle that is greater
by the maximum estimated error angle than the angular difference,
then rotates the body of the surveying instrument by the excessive
angle, and reverses the body of the surveying instrument if the
angular difference is smaller than the maximum estimated error
angle.
The invention according to Claim 4 is characterized in that, in the
invention according to Claim 1, if an angular difference of the
direction angle is greater than the sum of the maximum estimated
error angle of the azimuth angle sensor and a safe error angle
obtained by affording a margin for the error angle, the rotation
command means or the rotation means rotates the body of the
surveying instrument in a rotational direction determined based on
the angular difference, and, if the angular difference of the
direction angle is greater than the maximum estimated error angle
and is smaller than the sum of the maximum estimated error angle
and the safe error angle, the rotation command means or the
rotation means determines an excessive angle greater by the sum of
the maximum estimated error angle and the safe error angle than the
angular difference, then rotates the body of the surveying
instrument by the excessive angle, and reverses the body of the
surveying instrument, and, if the angular difference of the
direction angle is smaller than the maximum estimated error angle,
the rotation command means or the rotation means determines an
excessive angle greater by the maximum estimated error angle than
the angular difference and a return angle equal to the sum of twice
the maximum estimated error angle and the safe error angle, then
rotates the body of the surveying instrument by the excessive
angle, then reverses the body of the surveying instrument by the
return angle, and again rotates the body of the surveying
instrument in the direction determined first.
The invention according to Claim 5 is characterized in that, in the
invention according to any one of Claims 1, 2, 3, and 4, the
azimuth angle sensor is a magnetic sensor.
[Effects of the Invention]
According to the invention of Claim 1, the rotation command means
or the rotation means determines a rotational direction of the body
of the surveying instrument based on an angular difference between
a direction angle obtained when the target is caused to
substantially exactly face the surveying instrument at the last
measurement and a direction angle obtained when the target is
caused to substantially exactly face the surveying instrument at
the present measurement. Therefore, the instrument body can
automatically determine a rotational direction appropriate for
catching guide light emitted from the target by a minimum rotation
angle without imposing a burden on an operator, and the time
required for automatic collimation can be shortened as much as
possible without increasing a burden imposed on the operator, thus
making it possible to improve working efficiency.
According to the invention of Claim 2, the rotation command means
or the rotation means determines the rotation angle of the body of
the surveying instrument to be the angular difference. Therefore, a
case never occurs in which the surveying instrument fails to catch
guide light emitted from the target because of the influence of,
for example, noise, so that the instrument body is excessively
rotated, and hence the time taken until the guide light emitted
from the target is caught is prevented from becoming long.
According to the invention of Claim 3, the rotation command means
or the rotation means rotates the body of the surveying instrument
in a rotational direction determined based on the angular
difference if the angular difference is greater than a maximum
estimated error angle of the azimuth angle sensor, and the rotation
command means or the rotation means determines an excessive angle
that is greater by the maximum estimated error angle than the
angular difference, then rotates the body of the surveying
instrument by the excessive angle, and reverses the body of the
surveying instrument if the angular difference of the direction
angle is smaller than the maximum estimated error angle. Therefore,
the guide light emitted from the target can be caught by rotating
the instrument body by an appropriate rotational pattern in
accordance with the angular difference, and automatic collimation
can be reliably performed in a shorter time.
According to the invention of Claim 4, if an angular difference of
the direction angle is greater than the sum of the maximum
estimated error angle of the azimuth angle sensor and a safe error
angle obtained by affording a margin for the error angle, the
rotation command means or the rotation means rotates the body of
the surveying instrument in a rotational direction determined based
on the angular difference, and, if the angular difference of the
direction angle is greater than the maximum estimated error angle
and is smaller than the sum of the maximum estimated error angle
and the safe error angle, the rotation command means or the
rotation means determines an excessive angle greater by the sum of
the maximum estimated error angle and the safe error angle than the
angular difference, then rotates the body of the surveying
instrument by the excessive angle, and reverses the body of the
surveying instrument, and, if the angular difference of the
direction angle is smaller than the maximum estimated error angle,
the rotation command means or the rotation means determines an
excessive angle greater by the maximum estimated error angle than
the angular difference and a return angle equal to the sum of twice
the maximum estimated error angle and the safe error angle, then
rotates the body of the surveying instrument by the excessive
angle, then reverses the body of the surveying instrument by the
return angle, and again rotates the body of the surveying
instrument in the direction determined first. Therefore, the guide
light emitted from the target can be caught by rotating the
instrument body by an appropriate rotational pattern in accordance
with the angular difference, and automatic collimation can be
reliably performed in a shorter time.
According to the invention of Claim 5, the azimuth angle sensor is
a magnetic sensor. Therefore, the present invention can be easily
realized at low cost.
[Best Mode for Carrying Out the Invention]
Embodiments of the present invention will be hereinafter described
in detail with reference to the accompanying drawings.
First, a first embodiment of the present invention will be
described with reference to FIG. 1 to FIG. 3. FIG. 1 is a block
diagram of the whole of a survey system according to this
embodiment. FIG. 2 is a view for explaining the principle of the
present invention. FIG. 3 is a flowchart explaining a process for
adjusting the body of a surveying instrument approximately toward a
target in this survey system.
As shown in FIG. 1, the survey system has a target 60 including a
guide light transmitter 66, an azimuth angle sensor 86 that
measures the direction of the target 60, and a storage portion 88
that stores a direction angle (azimuth angle) measured by the
azimuth angle sensor 86. A central processing unit (CPU) 80 is
connected to the azimuth angle sensor 86 and the storage portion
88. The central processing unit (CPU) 80 causes the azimuth angle
sensor 86 to measure a direction angle and causes the storage
portion 88 to store this direction angle every time the distance
and angle are measured by moving the target 60. When the distance
and angle begin to be measured, the central processing unit 80
calculates an angular difference .theta.B-.theta.A between a
direction angle .theta.A obtained at the last measurement and a
direction angle .theta.B obtained at the present measurement, then
determines the rotational direction of an instrument body 52 in
accordance with the angular difference .theta.B-.theta.A, and
transmits a horizontal rotation command signal, which includes this
rotational direction, to the surveying instrument 50 by radio
65.
A magnetic sensor that outputs a direction angle by detecting
terrestrial magnetism is used as the azimuth angle sensor 86. The
direction angle is measured by a clockwise angle based on the
magnetic north. An example of such a magnetic sensor is disclosed
in Japanese Unexamined Patent Application Publication No. H9-329441
filed by the present applicant. Instead, an azimuth angle sensor
using a hall device may be used. Excluding this, the survey system
is identical in structure with the conventional survey system shown
in FIG. 6. Therefore, overlapping description of the structure of
this survey system is omitted.
Referring to FIG. 2, the principle of the present invention will be
described. When an operator measures the distance or the angle
while causing the target 60 to substantially exactly face the
surveying instrument 50 at point "A," the central processing unit
80 causes the azimuth angle sensor 86 to read a direction angle
.theta.A that the guide light transmitter 66 makes with the
direction N of the magnetic north, and causes the storage portion
88 to store the direction angle .theta.A. When the measurement is
completed at point "A," and the target 60 is moved to point "B,"
the target 60 is again caused to substantially exactly face the
surveying instrument 50, and the measurement is started. At this
time, the central processing unit 80 again causes the azimuth angle
sensor 86 to read the direction angle .theta.B of the guide light
transmitter 66, and calculates an angular difference
.DELTA..theta.=.theta.B-.theta.A between the direction angle
.theta.A at point "A" at the last measurement and the direction
angle .theta.B at point "B" at the present measurement. Since this
angular difference .DELTA..theta. is a change in the direction
angle of the surveying instrument 50 when viewed from the target
60, the instrument body 52 comes to substantially exactly face the
target 60 placed at point "B" by rotating the instrument body 52 by
this angular difference .DELTA..theta. in the opposite
direction.
Therefore, when this angular difference
.DELTA..theta.=.theta.B-.theta.A is in the relation
-180.degree..ltoreq..DELTA..theta.<0.degree. or
180.degree..ltoreq..DELTA..theta.<360.degree., a rotation
command signal including a counterclockwise rotational direction is
transmitted from the target to the surveying instrument 50, and,
when this angular difference .DELTA..theta.=.theta.B-.theta.A is in
the relation 0.degree..ltoreq..DELTA..theta.<180.degree. or
-360.degree..ltoreq..DELTA..theta.<-180.degree., a rotation
command signal including a clockwise rotational direction is
transmitted from the target to the surveying instrument 50, whereby
the instrument body 52 is rotated in a specified direction.
Accordingly, an appropriate rotational direction can be
automatically determined with respect to the instrument body 52
without imposing a burden on the operator, and the guide light
transmitter 66 can always be caught by a minimum rotation angle
within 180.degree.. Therefore, working efficiency can be
improved.
If the angular difference .DELTA..theta. is near .+-.0.degree., the
guide light 66 can be caught without the rotation of the instrument
body, and, if the angular difference .DELTA..theta. is near
.+-.180.degree., the time taken until the guide light transmitter
66 is caught becomes almost the same in spite of the clockwise or
counterclockwise rotation. Therefore, the azimuth angle sensor 86
is not required to be so accurate, and there is no need to cause
the target 60 to exactly face the surveying instrument 50 when
measured. Therefore, it is permissible to cause the target 60 to
roughly face the surveying instrument 50.
A description will now be given of the measuring process of the
survey system with reference to the flowchart of FIG. 3.
When this survey system is started, the process proceeds to step
S21, at which the target 60 sends a measurement starting command to
the surveying instrument 50. When the surveying instrument 50
receives the measurement starting command, the process proceeds to
step S91, at which a guide light ON command is transmitted to the
target 60. When the target 60 receives the guide light ON command
at step S22, the process proceeds to step S23, at which guide light
64 is output from the guide light transmitter 66. The process then
proceeds to step S24, at which the target 60 obtains a direction
angle .theta.B from the azimuth angle sensor 86, and the direction
angle .theta.B is stored in the storage portion 88. The process
then proceeds to step S25, at which the target 60 calculates an
angular difference between the direction angle .theta.B obtained at
the present measurement and the direction angle .theta.A obtained
at the last measurement. The process then proceeds to step S26, at
which a rotational direction indicated to the surveying instrument
50 is determined. The process then proceeds to step S27, at which a
horizontal rotation command including the rotational direction is
transmitted to the surveying instrument 50. Herein, steps S24 to
S27 executed by the central processing unit 80 correspond to the
rotation command means of the present invention.
When the surveying instrument 50 receives the horizontal rotation
command at step S93, the process proceeds to step S103, at which
the instrument body 52 is horizontally rotated. The process then
proceeds to step S104, at which the guide light 64 is detected, and
thereby the horizontal direction of the target 60 is detected. If
the guide light 64 cannot be received in predetermined time here,
the process proceeds to step S105, at which an error notice is
transmitted to the target 60. When the target 60 confirms the error
notice at step S4, the process proceeds to step S5, at which a
horizontal detection error is displayed on the display 84, and the
operations are stopped. When the guide light 64 is received at step
S104, it is determined that the horizontal direction of the target
60 has been detected. The process then proceeds to step S106, at
which the horizontal position of the telescope 54 is adjusted
toward the guide light transmitter 66, and the horizontal rotation
of the instrument body 52 is stopped. Herein, steps S93 to S106
executed by the central processing unit 100, the direction detector
56, the horizontal driving portion 104, and the horizontal motor
102 correspond to the rotation means of the present invention.
Since steps subsequent to this are the same as the conventional
ones shown in FIG. 8, a description thereof is omitted. In a case
in which the horizontal detection error is displayed on the display
84, and the operations are stopped, it is recommended to first
remove the cause of the error, and then re-start the operation of
the survey system.
According to this embodiment, since the guide light 64 is a fan
beam that is wide in the horizontal direction and that is narrow in
the vertical width, the guide light 64 can reach a distant place,
and, since the guide light 64 is caused to scan in the vertical
direction and is projected onto a wide range from side to side and
up and down, the direction detector 56 mounted on the surveying
instrument 50 can reliably receive the guide light 64 and can
reliably perform collimation preparations for pre-directing the
telescope 54 approximately in the direction of the target 60 before
starting automatic collimation regardless of a large vertical
interval between the surveying instrument 50 and the target 60 even
if the surveying instrument 50 and the target 60 do not exactly
face each other. Moreover, an appropriate rotational direction can
be automatically indicated from the target 60 to the surveying
instrument 50 in addition to transmitting the guide light 64, and
the instrument body 52 can always receive the guide light 64 by the
minimum horizontal rotation within 180.degree.. Thus, an
appropriate rotational direction of the instrument body 52 is
automatically determined and is given to the surveying instrument
50. Therefore, working efficiency can be improved without imposing
a burden on an operator.
A second embodiment will now be described. A survey system in this
embodiment has the same structure as in the first embodiment shown
in FIG. 1, but differs in the process for positionally adjusting
the instrument body 52 toward the target 60. This process will be
hereinafter described with reference to FIG. 4 and FIG. 5.
As shown in FIG. 4, after starting the survey system, the process
proceeds to step S25, at which the target 60 calculates an angular
difference .DELTA..theta.=.theta.B-.theta.A between the direction
angle .theta.B obtained at the present measurement and the
direction angle .theta.A obtained at the last measurement in the
same way as in the first embodiment.
The process then proceeds to step S30, at which a comparison as to
whether it is greater or smaller is made between the angular
difference .DELTA..theta. between the direction angle .theta.B
obtained at the present measurement and the direction angle
.theta.A obtained at the last measurement and the maximum estimated
error E of the azimuth angle sensor 86. When a magnetic sensor is
used as the azimuth angle sensor 86, the maximum estimated error E
is estimated at about 30.degree. or less, in consideration of a
situation in which a structure made of magnetic materials or the
like exists near the sensor. Besides this, when an operator causes
the target 60 to exactly face the surveying instrument 50, there is
a possibility that the error of about 5.degree. at its maximum will
occur. For this reason, it is normal to estimate the maximum
estimated error E at about 35.degree.. Therefore, if an angular
difference between direction angles at measurement points "A" and
"B" is represented as .DELTA..theta. when the target 60 is moved
from measurement point "A" to measurement point "B" as shown in
FIG. 5, the guide light 64 can be reliably detected by rotating the
instrument body 52 so as to search the guide light 64 within the
range of .DELTA..theta..+-.E, i.e., .DELTA..theta..+-.35.degree..
The maximum estimated error E may be, of course, increased or
decreased in a suitable manner according to, for example, an
external environment.
If .DELTA..theta.>E at step S30, the process proceeds to step
S31, at which the rotational direction of the instrument body 52 is
determined in the same way as in the first embodiment as shown in
FIG. 5(A), and a rotation command of a rotational pattern P1 by
which the instrument body 52 is simply rotated in an indicated
rotational direction is formed. This rotational pattern P1 makes it
possible to cover .DELTA..theta..+-.E, which is an error range of
.DELTA..theta., swiftly and reliably.
If .DELTA..theta..ltoreq.E at step S30, the process proceeds to
step S32, at which the rotational direction of the instrument body
52 is determined as shown in FIG. 5(B), and an excessive angle
.theta.1=.DELTA..theta.+E, which is greater by the maximum
estimated error E than the angular difference .DELTA..theta., is
determined, and a rotation command of a return-type rotational
pattern P2, by which the instrument body 52 is first rotated by the
excessive angle .theta.1, is then reversed by the return angle
.theta.2, and continues to be rotated in the same direction without
changes, is formed. This rotational pattern P2 makes it possible to
cover .DELTA..theta..+-.E, which is an error range of
.DELTA..theta., swiftly and reliably. Especially when the
instrument body 52 is rotated in an incorrect direction because of
the error of .DELTA..theta., the guide light 64 can be swiftly and
reliably caught by the minimum rotation angle of the instrument
body 52.
When the rotation commands are formed in this way, the process
proceeds to step S27, at which a rotation command is transmitted
from the target 60 to the surveying instrument 50. Herein, on the
side of the surveying instrument 50, steps S24, S25, S30 to S32,
and S27 executed by the central processing unit 80 correspond to
the rotation command means of the present invention.
When the surveying instrument 50 receives a horizontal rotation
command at step S93, the process proceeds to step S103, at which
the instrument body 52 is horizontally rotated. The process then
proceeds to step S104, at which the guide light 64 is detected, and
the horizontal direction of the target 60 is detected. Since steps
subsequent to this are the same as the conventional ones shown in
FIG. 3, a description thereof is omitted.
According to this embodiment, if the angular difference
.DELTA..theta. is greater than the maximum estimated error angle E
of the azimuth angle sensor 86, the rotational pattern P1 is
selected, and, if the angular difference .DELTA..theta. is smaller
than the maximum estimated error E, the return-type rotational
pattern P2 is selected. Additionally, the instrument body 52 is
rotated by an appropriate rotational pattern in accordance with the
angular difference .DELTA..theta., and the guide light 64 emitted
from the target 60 is caught swiftly and reliably. Therefore, the
appropriate rotational direction of the instrument body 52 can be
automatically determined and be given to the surveying instrument
50 without increasing the burden imposed on an operator, and
working efficiency can be heightened.
A third embodiment will now be described with reference to FIG. 6
and FIG. 7. A survey system of this embodiment is formed by
improving that of the second embodiment. As shown in FIG. 6, as the
maximum error range in which the target 60 that has been moved is
placed, a safe error angle E obtained by affording a margin for the
error angle is set outside a normally expected maximum estimated
error angle E', in order to further increase the reliability of the
capture of the target 60. Normally, the safe error angle E' is set
at about 30.degree.. The safe error angle E' may be, of course,
increased or decreased in a suitable manner according to, for
example, an external environment.
In the flowchart of FIG. 7, an angular difference .DELTA..theta.
between the direction angle .theta.B obtained at the present time
and the direction angle .theta.A obtained at the last time is
calculated at step S25 in the same way as in the second embodiment
shown in FIG. 4. However, in this embodiment, the process then
proceeds to step S40, at which a comparison is made among the
angular difference .DELTA..theta., the maximum estimated error
angle E and the safe error angle E'.
If E+E'<.DELTA..theta. among the angular difference
.DELTA..theta. between the direction angle .theta.B obtained at the
present time and the direction angle .theta.A obtained at the last
time, the maximum estimated error angle E and the safe error angle
E', the process proceeds to step S41, at which the rotational
direction of the instrument body 52 is determined in the same way
as in the first embodiment, and a rotation command of a rotational
pattern P1 by which the instrument body 52 is simply rotated in an
indicated rotational direction is formed (see FIG. 6(A)).
If E<.DELTA..theta..ltoreq.E+E', the process proceeds to step
S42, at which the excessive angle .theta.1 is determined as
.theta.1=.DELTA..theta.+E+E', and a rotation command of a
return-type rotational pattern P2, by which the instrument body 52
is rotated by the excessive angle .theta.1, and continues to be
reversed (see FIG. 6(B)).
If .DELTA..theta.<E, the process proceeds to step S43, at which
the excessive angle .theta.1 is determined as
.theta.1=.DELTA..theta.+E, and the return angle .theta.2 is
determined as .theta.2=E+E+E', and a rotation command of a
return-type rotational pattern P3, by which the instrument body 52
is first rotated by the excessive angle .theta.1, is then reversed
by the return angle .theta.2, and is rotated in the first
direction, is formed (see FIG. 6(C)).
After determining the rotational patterns P1, P2, and P3 in this
way, the process proceeds to step S27, and steps subsequent to this
step are carried out in the same way as in the second embodiment
shown in FIG. 4.
In this embodiment, .DELTA..theta..+-.E.+-.E', which is the error
range of .DELTA..theta., is covered swiftly and reliably so as to
reduce mistakes in catching the target 60. Therefore, in this
embodiment, working efficiency can be more excellently raised than
in the second embodiment.
The present invention is not limited to the embodiments described
above. For example, various modifications can be carried out as
follows.
In the above embodiments, the rotational direction is determined by
the central processing unit 80 which is a rotation command means
provided on the side of the target 60. However, it is permissible
to transmit measured direction angles .theta.A and .theta.B from
the side of the target 60 to the side of the surveying instrument
50 and determine the rotational direction by the central processing
unit 100 which is a rotation means provided on the side of the
surveying instrument 50. Likewise, the same effect as in the above
embodiments can be fulfilled in this case.
In the above embodiments, a low-cost magnetic sensor is used as the
azimuth angle sensor 86. However, any sensor can be used as the
azimuth angle sensor 86 if the sensor is a direction-angle
detectable sensor such as a gyro that always maintains a constant
posture or a wireless direction-finder that detects the incoming
direction of radio waves emitted from a fixed radio source like a
broadcasting station.
In the above embodiments, the direction angle is obtained and
stored at step S24 (see FIG. 3 and FIG. 5). However, the direction
angle may be obtained and stored at any step between the start and
step S25.
In the above embodiments, the guide light 64 shaped like a fan beam
is emitted from the target 60 while scanning. However, a beam of
guide light 64 that is simple diffused light may be emitted.
In the first embodiment, only the rotational direction of the
instrument body 52 is indicated from the target 60 to the surveying
instrument 50. However, it is permissible to also transmit an
angular difference .DELTA..theta.=.theta.B-.theta.A serving as the
rotation angle from the target 60 to the surveying instrument 50
and stop the instrument body 52 when the instrument body 52 is
directed approximately toward the target 60. In this case, the
instrument body 52 is never rotated excessively, and the time taken
until the automatic collimation is more swiftly completed can be
shortened.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 Block diagram of the whole of the survey system according to
the first embodiment of the present invention.
FIG. 2 View for explaining the principle of the survey system.
FIG. 3 Flowchart explaining a process for positionally adjusting
the instrument body approximately toward the target in the survey
system.
FIG. 4 Flowchart explaining a process for positionally adjusting
the instrument body approximately toward the target in the survey
system according to the second embodiment of the present
invention.
FIG. 5 View for explaining a rotational pattern by which the
instrument body is rotated in the survey system according to the
second embodiment.
FIG. 6 View for explaining a rotational pattern by which the
instrument body is rotated in the survey system according to the
third embodiment of the present invention.
FIG. 7 Flowchart explaining a process for positionally adjusting
the instrument body approximately toward the target in the survey
system according to the third embodiment.
FIG. 8 View showing the outline of the conventional survey
system.
FIG. 9 Block diagram of the whole of the conventional survey
system.
FIG. 10 Flowchart explaining the measuring process of the
conventional survey system.
DESCRIPTION OF THE SYMBOLS
50 Surveying instrument 52 Instrument body 60 Target 64 Guide light
66 Guide light transmitter 80 Central processing unit (rotation
command means) 86 Azimuth angle sensor 100 Central processing unit
(rotation means) .DELTA..theta. Angular difference between a
direction angle obtained at the present time and a direction angle
obtained at the last time .theta.1 Excessive angle .theta.2 Return
angle E Maximum estimated error angle E' Safe error angle
* * * * *